Let's set up a proportion.
16/x= 80/100
16*5=80
x*5=100
x=20
Final answer: 20 questions total
Answer:
width = 2 cm
Step-by-step explanation:
are of rectangle is equal to length times width
x is the width, then length is 3x + 4
so x(3x + 4) = 20
3x^2 + 4x = 20
3x^2 + 4x - 20 = 0
The formula to solve a quadratic equation of the form ax^2 + bx + c = 0 is equal to x = [-b +/-√(b^2 - 4ac)]/2a
so a = 3
b = 4
c = -20
substitute in the formula
x = [-4 +/-√(4^2 - 4(3)(-20))]/2(3)
x = [-4 +/- √(16 + 240)]/6
x = [-4 +/- 16]/6
x1 = (-4 + 16)/6 = 2
x2 = (-4 - 16)/6 = -20/6
since the width can't be a negative number, x2 is not the right answer
so x = 2
Answer:
At 2pm, the diver dive down -45ft away from the sea level
Set p(x) = 0 and solve for x.
x^3 - 4x^2 + 3x - 12 = 0
x^3 - 4x^2 ... + 3x - 12 = 0, cut in half and factor
x^2 (x-4) ... +3 (x-4) = 0, regroup
(x^2 + 3) (x-4) = 0, set each part equal to zero and solve
x^2 + 3 = 0, subtract 3 from both sides
x^2 = -3, take square root of both sides
x = sqrt (-3) which is imaginary.
x-4 = 0, add 4 to both sides
x = 4
Since we do not want complex/imaginary numbers involved, our answer is 4. They will break even in 4 years.